Sheet feeding apparatus



NOV- 23, 1965 D. H. GEIGENMILLER ETAL 3,218,897

SHEET FEEDING APPARATUS 3 Sheets-Sheet 1 Filed Deo. 27, 1962 @m TMI IUI.

I l IMJ BY A TTORIXS N0v 23, 1965 D. H. GEIGENMILLER ETAL 3,213,897

SHEET FEEDING APPARATUS 3 Sheets-Sheet 2 Filed Dec. 27. 1962 mms m OMM ,M R N T. EET T VPIUT A NEA IGM mm um DW m .lm ,q QmUmOu N m y rm.

N @Px Nov. 23, 196.5 D. H. GEIGENMILLl-:R ETAL 3,218,897

SHEET FEEDING APPARATUS 3 Sheets-Sheet 3 Filed D60. 27. 1962 INVENTORS DUDLEY i-I. GEIGENMILLER WILLIAM G. MATTHEWS A TTORNE YS United States Patent 3,218,897 SHEET FEEDING APPARATUS Dudley H. Geigenmiiler, Baltic, and William G. Matthews, Fitchville, Conn., assignors to Smith t Winchester Manufacturing Company, South Windham, Conn., a corporation of Connecticut Filed Dec. 27, 1962, Ser. No. 247,717 19 Claims. (Cl. SI5-8S) This invention relates generally to appara-tus for handling sheet material and, more particularly, to improved sheet handling apparatus particularly suitable for high speed handling of paper sheets being fed from a shear to stacking apparatus.

A principal object of this invention is to provide sheet feeding apparatus including an improved device for overlapping successive sheets as they are being fed.

Another object of this invention is to provide improved sheet feeding apparatus which automatically rejects a defective sheet from the main feed path While smoothly maintaining the ow of flawless shee-ts and which can maintain the desired overlap between successive sheets even though one of the sheets has been rejected Still another object of this invention is to provide irnproved sheet handling apparatus capable of handling simultaneously a plurality of sheets -being fed along independent paths in the manner set forth in the preceding objects.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

The invention accordingly consists of the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth and the scope of the application which will be indicated in the appended claims.

In the drawings:

FIG. l is a diagrammical side elevational View of a sheeter and dual layboy apparatus embodying this invention;

FIG. 2 shows in greater detail the central parts of FIG. l;

FIG. 3 is an enlarged view of the sheet deecting mechanism shown in FIG. 2;

FIG. 4 is an enlarged view of the sheet overlapping mechanism shown in FIGURE 2;

FIG. 5 is a cross-sectional view taken along lines 5-5 of FIG. 3;

FIG. 6 is a cross-sectional View taken along lines 6 6 of FIG. 4;

FIG. 7 is a cross-sectional view taken along llines 7 7 in FIG. 2; and

FIG. 8 is a schematic diagram of the photoelectric circuit which automatically controls suction valves for holding the sheets when a reject occurs.

With reference to FIG. l, illustrating typical apparatus utilizing a preferred embodiment of this invention, there is shown a roll 10 of sheet material, such as paper, which is mounted on an unwind assembly 12. The paper web 14 is fed through a suitable electronic aw detector 16 shown in the preferred embodiment as being of the photoelectric type which produces an electrical signal whenever there appears in the web a aw such as a tear or perforation.

From the aw detector 16, web 14 is fed over an idler roll 18 and then past slitter Iblades 20 which sever the paper into longitudinal strips of a desired width. The paper web 14 is then passed through driven feed rolls 22 and fed to a stationary bed knife cutter 24 which cooperates with a rotary knife 26 to cut the web into sheets of a desired length. Feed rolls 22 and rotary knife 26 may be driven by a common variable speed drive (not shown) or by any other type of driving arrangement which would rotate the knife 26 and feed rolls 22 at the desired rotary speeds. Rotary knife 26 is thereby synchronized with feed rolls 22 and the relative speeds therebetween determine the length of the sheets cut by the rotary knife in "cooperation with the bed knife 24.

Considering only one group `of sheets being fed longitudinally through the apparatus (each of the group of sheets formed by slitter 20 is handled in the same manner) it is observed that after a sheet leaves the cutter 26, it is fed between a plurality of narrow, high-speed conveyor belts or tapes 28 and 30. When no aw has been sensed by the electronic detector 16, the sheets pass directly to high-speed tapes 32 and through a photoelectric sheet sensing device 34 comprising a light source and a photocell 38.

It is to be noted ithat the leading edge of each sheet is actually engaged by the fast tapes 28 and 30 before the sheet is cut by the rotary knife 26 to form a trailing edge. As a sheet is cut by each rotation of rotary knife 26, the sheet is separated from the web passing through feed rolls 22 by the fast take-away tapes 28 which are traveling at a linear speed approximately ten percent greater than the speed at which the web is passing through feed rolls 22 thereby producing a predetermined normal gap between the trailing edge of a cut sheet and the leading edge of the following web. Such an arrangement eliminates any possibility of the trailing edge of a cut sheet interfering with the leading edge of following web being fed onto the fast take-away tapes 28 prior to being cut by rotary knife 26.

After passing through the photoelectric device 34, each sheet passes into an overlap section which is shown in FIG. 2 and in greater detail in FIG. 4, sheet overlap being a requisite step in the slowing down of the sheets prior to stacking. Each sheet is fed from the fast tapes 32 over a stationary plate 40 to a plurality of slow speed tapes 42 which are positioned approximately parallel to, but somewhat lower than, tapes 32. These slowspeed tapes may be driven by a suitable variable speed drive (not shown) to permit a variation in the speed of the overlapped sheets for proper removal thereof from the overlap section and subsequent stack- A driven overlap roll 44 forms a nip with a roll 46 and by reason of its position and design applies a tangential force to the paper sheets to provide a positive driving action and control of the sheets being fed along slow tapes 42. In the prior art, many sheet feeding and stacking machines utilized a roll such as overlap roll 44 as a braking roll for decelerating the sheets. Since such an arrangement required that the sheets be decelerated at their leading edges, buckling of the sheet often resulted thereby causing jamming of sheets at high speeds and, consequently requiring shutting down of the machine,

thereby reducing the operating efficiency of the machine. Moreover, the over-all result necessitated comparatlvely slow speed operation of the over-all apparatus.

However, in the overlap section shown in FIGS. 2 and 4, overlap roll 44 is adjustably positioned along the length of tapes 42 so that, as the trailing edge of each sheet drops from the fast tapes 32 onto the stationary plate 40, the leading edge of the sheet is spaced away from the center line of overlap roll 44.'

The overlapping of successive sheets is produced by the action of a rotating suction drum 48 and one or more solenoid operated valves 62.` A suitable vacuum source (not shown) is connected to the interior of drum 48 containing an elongated aperture 52 which is rotatable into alignment with a corresponding elongated aperture S4 formed in stationary plate 40. The alignment of aperture 52 in drum 48 with aperture 54 in plate 40 creates a sucltion at aperture 54 which is coordinated with the passage of each sheet to act on the trailing edge of Va sheet .on plate 40 to retard or slow down the sheet. By retarding each sheet in this manner, the leading edge of the following sheet drops olf tapes 32 .to overlap the trailing edge of the retarded sheet.

Also formed in stationary plate 40 are a series of c1rcular apertures S8 spaced to the right of aperture 54 as seen in FIG. 4. Communicating with aperture 58 is a conduit 60 connected to a threeway, solenoid-actuated valve 62. In its deenergized position, valve 62 connects conduit 60 to a source of forced air which emanates from aperture 58 to assist in the feeding of the sheets across plate 40. In its energized position, valve 62 connects a conduit 60 to a source of vacuum which produces a suction at aperture 58 in plate 40 for the purpose of controlling the ow of sheets when a reject occurs as hereinafter described.

With reference once again to FIG. l, the overlapped sheets are fed along slow tapes 42 to a layboy or a sheet stacking device 56 upon which they are ejected to form a stack 57. Layboy 56 itself forms no part of this invention and operates to maintain the top of stack 57 at a substantially constant level to receive the sheets being ejected from slow tapes 42. Layboy 56 includes suitable joggers for jogging the sheets both in a longitudinal and transverse direction in order to form a neat, uniform stack of sheets.

In the foregoing general discussion, it was assumed that no flaw was sensed by the flaw detector 16. However, should a flaw occur in the paper web 14, an electrical signal is generated by flaw detector 16 in order to energize corresponding solenoids at the proper time to deflect the I.

sheet containing a flaw downwardly along a reject path formed by the inclined portion 68 of fast take-away tapes 28. Fingers 64 operate upon the top surface of the sheet to be rejected and cooperate with a V-shaped deflecting member 70 to direct the rejected sheet along the tapes 68. Another set of high-speed tapes 72 cooperates with the tapes 68 in order to direct the rejected sheet to still another set of fast tapes 74 which correspond to the fast tapes 32 described in connection with the normal path of the cut sheets. These rejected sheets are then fed through a photoelectric gap detecting device 34a which is identical to the gap detecting device 34. The sheets are then fed into an overlap section which is identical to the overalp section described in connection with the normal feed path and parts of this overlap section bear the same reference numeral followed by the letter a as the corresponding parts in the overlap section in the normal feed path as shown in FIG. 4.

The fingers must be operated at the proper times so that the sheet containing the flaw sensed by detector 16 is the one which is actually rejected. The timing of the operation of the fingers 64 is determined by the speed of movement of the fingers as well as distance between the flaw detector 16 and the fingers 64 and also by the relative speed of the rotary knife 26 and the fast take-away tapes 28. Fingers 64 act as gates and are actuated in the preferred embodiment when the trailing edge of the sheet preceding the one to be rejected is underneath the lingers. The amount of torque and the shape of the fingers are so designed that the speed of the preceding sheet is not retarded. However, as soon as this preceding sheet passes from beneath fingers 64, the fingers drop into the gap created by the fast take-away tapes 28 as shown best in FIG. 3. Consequently, the following sheet, which is the one containing the flaw, is diverted along the inclined fast tapes 68 to the reject section and its associated overlap section to form a stack 57a on a second layboy 56a.

Even though a sheet is rejected, the apparatus of this invention permits the preceding sheets to continue uninterrupted travel towards the layboy. However, there is a substantial likelihood that the leading edge of the sheet following the rejected sheet will engage the trailing edge of the sheet preceding the rejected sheet because the preceding sheet will be traveling on the slow tapes 42 whereas the following sheet is on the fast tapes 32. Such engagement is likely to cause sheet buckling and jamming thereby the following sheet is on the fast tapes 32. Such engagefunctioning is prevented by the apparatus of this invention by holding the sheet preceding the rejected sheet on plate 40 until the sheet following the rejected sheet (or sheets) overlaps the preceding sheet in the normal manner. This action is accomplished by maintaining the valve 62 in its energized condition as soon as a reject occurs so that a sheet preceding a reject is retained by suction at aperture 58 against stationary plate 40 until another flawless sheet is available to be overlapped with the retained sheet whereupon the sheets are released for travel to layboy 56. Valve 62a in the overlap section associated with the reject section functions in an identical manner to retain each sheet preceding a gap in the flow of reject sheets to layboy 56a.

Turning now to a description of the overlap section in greater detail, suction drum 48 is rotated by suitable drive means in synchronism with the rotary knife 26, that is one revolution of suction drum 48 occurs during the passage of each sheet. A vacuum is created underneath the trailing edge of each sheet each time the slots 52 and 54 are in communication. Stationary plate 40 is substantially horizontally aligned with slow-speed tapes 42 and is parallel but lower than fast take-away tapes 32 .in order to insure that all positive driving force is removed from the paper sheets before they drop onto plate 40.

FIG. 6 shows a cross section ofthe overlap section taken along line 6-6 in FIG. 4. A vacuum inlet conduit 84 is connected to the interior of the hollow suction drum 48. Flanges 85 and 86 depend from plate `40 to form a partial seal about the surface of the drum and create a better suction at aperture 54.

With reference to FIG. 4, an arcuate cani member 78 is fixed to the surface of drum 48 at a point diametrically opposite from aperture 52. Mounted adjacent drum 48 is a switch 82 which is effectively connected in series with the energizing circuit for the solenoid valve 62. When cam member 78 is in engagement with a switch actuator 80 mounted on switch 82, the switch is open and the energization circuit for solenoid valve 62 is thereby disabled.

The operation of the overlap section will now be described with reference to FIGS. 4 and 8. When there is no reject, the gap caused by each sheet being pulled away by fast tapes 28 from cutter 26 is sensed by photoelectrie detector 34. As a result, light impinges upon photocell 38 to energize the associated amplifier 87. Switch 82 is electrically connected between amplifier 87 and a relay coil SS which closes contacts 89 when it is energized. Drum 48 rotates into position to create a vacuum at aperture 54 when each sheet passes over plate 40, thereby retarding -the sheet. However, at this time, carn member 78 is in engagement with actuator S to open switch 82 so that relay 88 is not energized and contacts 89 remain open so that solenoid 90 of valve 62 is not energized.

As drum 48 continues to rotate, cam member 78 becomes disengaged from switch actuator 80 so that switch 82 is closed. However, solenoid 91 is not energized since photocell 38 has sensed the following sheet and amplifier 87 =is not energized. Consequently, valve 62 is in its nonactuated condition so that forced air is applied to aperture 58 to facilitate removal of the sheet from plate 40 thereby to aid slow tapes 42 in feeding the sheets to the layboy 56.

When a reject occurs and a sheet has been defiected into the reject path, photocell 38 does not sense a following sheet and amplifier 87 remains energized even after the cam switch 82 has closed. Therefore, solenoid valve 62 is energized to create a vacuum at aperture 58 to stop and hold the sheet which has already been retarded or slowed down by the vacuum provided by suction drum 4S. The vacuum produced by one or more valves 62 may not be sufficient to stop or hold a sheet; therefore, under such a condition, it is important that suction drum 48 and valve 62 be properly synchronized so that valve 62 is energized immediately after a sheet has been retarded by aperture 54. When the next following flawless sheet interrupts the lighting falling on cell 38, valve 62 is deenergized, the following sheet overlaps the held sheet which is released by the forced air and fed to the layboy 56.

FIG. 5 shows a cross section of the reject section similar to a view taken along lines 5-5 in FIG. 3 except that the embodiment of finger mounting illustrated provides for common actuation of groups of fingers rather than providing a separate relay to actuate each finger. For purposes of illustration, fifteen fingers 64 are shown in their downward or sheet-rejection position and these fingers are fixed or keyed to a common shaft 93 which is rotatably mounted on the supporting rod 92. Shaft 93 is rotated by means of a suitable linkage 94 which is actuated by a solenoid (not shown) energized by the signal produced by fiaw detector 16.

The second or right-hand group of fingers 96 are shown in FIG. 5 in their upward or normal position. These fingers are operated by a linkage 98 which may be actuated by another solenoid (not shown) energized by detector 16 to operate upon a second group of sheets formed by slitters 20. The number of fingers and the spacing thereof depends upon the number and width of sheets being handled. Smaller and larger numbers of fingers may be grouped together for common actuation, and their associated solenoids may be electrically interconnected tov energize two or more groups simultaneously when extremely wide sheets are being handled. Additionally, when each finger is provided with its own operating solenoid, it is Observed that maximum control fiexibility is obtained.

FIG. 7 shows a cross section of the tapes taken along lines 7-7 in FIG. 2. Overlap roll 44 takes the form of a plurality of speed rolls 43 fixed to a common shaft 45. Rolls 43 have a larger diameter than shaft 45 to form recesses through which fast belts 30 pass to permit a sheet carried by slow belts 42 to be engaged by the rolls 43.

Switches 91 shown in FIG. 8 may be mounted on a control panel in order to interconnect electrically two valves 62, 62a so that a single photocell controls both valves. For example, if switch 91 is moved to its B position and switch 91A is in its B position, then both solenoids 90 and 90A are controlled by the photocell 38 which solenoids function to actuate their respective valves 62, 62a.

In FIG. 2 there are shown suitable tensioning devices and 102 for adjusting the tension of the tapes passing therethrough.

While not illustrated, it is understood that the electrical signal generated by the flaw detector 16 can be utilized in a conventional manner to selectively eergize the solenoids associated with each finger in the embodiment of FIG. 3 or can be utilized to energize the solenoid controlling groups of fingers as shown in FIG. 5. Depending upon whether or not a slitter is utilized and upon how many parallel sheet fiow paths are to be provided, groups of solenoids can be selectively energized by use of suitable switching when the embodiment of FIG. 3 is utilized. Similarly, groups of fingers can be controlled by suitable energization of the group solenoids when the embodiment of FIG. 5 is utilized thereby to provide real control flexibility in the rejection of defective sheets of virtually any width.

From the foregoing description of the construction and operation of this apparatus, it is believed apparent that an extremely high-speed sheet handling device is provided whereby malfunctions caused by sheet interference are virtually eliminated and fiaw detection and sheet separation are accomplished without mpairing the speed of operation.

As will be apparent to persons skilled in the art, various modifications and adaptations of the structure above described will become readily apparent without departure from the spirit and scope of the invention, the scope of which is defined in the appended claims.

We claim:

1. In sheet feeding apparatus including means for feeding a plurality of sheets along a path, a sheet overlapping device comprising means fixed in position for retarding the trailing edge of each sheet and displacing said edge relative to the leading edge of a following sheet as it passes a predetermined location in the path so that the leading edge of a following sheet overlaps said trailing edge.

2. In sheet feeding apparatus including means for feeding a plurality of sheets along a path, a sheet overlapping device comprising means for retarding the trailing edge of each sheet as it passes a predetermined location in the path so that the leading edge of a following sheet overlaps said trailing edge, means for creating a gap between successive sheets, further means associated with said overlapping device and responsive to a gap between one sheet and a following sheet to hold said one sheet at said location so that the following sheet overlaps said one sheet.

3. A sheet feeding apparatus comprising means for conveying a plurality of sheets along a first path, sensing means responsive to a flaw in one of said sheets for directing said one sheet along a second path whereby'a gap is formed between the sheets being fed along said first path, means responsive to a gap between sheets to stop and hold the sheet preceding the gap, and means responsive to the presence of a following sheet at a predetermined point in said first path to release said preceding sheet thereby to overlap the sheet preceding the gap with the following sheet.

4. A sheeter and dual layboy apparatus comprising means for holding a roll of web material, means for feeding said web material along a first path, fiaw detecting means for detecting fiaws in said web material, means for cutting said web material into a plurality of sheets spaced apart by a normal gap of a predetermined length, means responsive to said flaw detecting means for directing a sheet containing a flaw to a second path whereby an excessive gap greater than said normal gap is formed between successive sheets being fed along said first path, each of said first and second paths including an overlapping device, each overlapping device comprising suction means for retarding the traialing edge of each sheet passing thereover so that overlap occurs between successive sheets spaced apart by said normal gap in each path, additional suction means in each path responsive to an .excessive gap between successive sheets for retaining each sheet preceding an excessive gap and responsive to the reduction of the gap to said normal gap to release the retained sheet, a sheet stacking device at the end of each path, and means to feed the overlapped Sheets in each path to the stacking device associated therewith.

5. A sheet handling and stacking apparatus comprising means to cut a web into a plurality of sheets, means the web, means responsive to said detecting means to deect a sheet containing a fiaw from said path, thereby creating an excessive gap between successive sheets in said path, signal means associated with said path to sense an excessive gap, second suction means operated in response to said signal means and associated with said first suction means for holding a retarded sheet preceding an excessive gap so that the first sheet following the excessive gap overlaps said retarded sheet, said signal means being responsive to a sheet following an excessive gap in said path to render said second suction means inoperable whereby said held sheet is released.

7. A sheet handling and stacking apparatus as defined in claim 3, further comprising second suction means for overlapping the defiected sheets, a second stacking device,

means to feed the overlap deflected sheets to said second stacking device.

8. In a sheet handling machine, first sheet conveying means, second sheet` conveying means spaced from said first sheet conveying means to define a gap in the sheet fiow path, sheet directing means independent of said sheet conveying means positioned above the sheet flow path and the gap, means for selectively moving said sheet directing means about an axis disposed above the sheet fiow path to a position extending into the gap thereby to deflect sheets leaving said first conveying means into said gap.

9. The machine as set forth in claim 8 wherein third conveying means are positioned below the gap to carry deflected sheets away from the gap.

10. The sheet handling machine as set forth in claim 8 wherein said sheet directing means comprises a plurality of fingers mounted for coaxial rotational movement about an axis generally perpendicular to the direction of sheet ow, the length of said fingers being sufiicient to extend into the gap when rotated downwardly toward said first sheet conveying means.

11. The sheet handling machine as set forth in claim 10 wherein each linger is provided with a separate actuator.

12. In sheet feeding apparatus including means for feeding a plurality of sheets along a path, a sheet overlapping device comprising a plate disposed below the level of the sheet feeding path onto which the advancing sheets are fed, an aperture in said plate and means for selectively applying suction to said aperture, said means being synchronized with the flow of sheets whereby said means is energized to apply the suction braking force to the trailing edge of the sheet on said plate.

13. The apparatus as set forth in claim 12 wherein said plate is provided with a second aperture and means are provided to blow air through Said aperture after a sheet has been braked thereby to assist the braked sheet to Vleave the plate.

14. In sheet feeding apparatus including means for feeding a plurality of sheets along a path, a sheet overlapping device comprising a plate onto which the advancing sheets are fed, an aperture in said plate and means for selectively applying a suction to said aperture, said means being synchronized with the flow of sheets whereby said means is energized to apply the suction brake force to the trailing edge of the sheet on said plate, a second aperture in said plate and means for selectively blowing air through said second aperture after a sheet has been braked thereby to assist the braked sheet to leave the plate and for applying suction to said second aperture thereby to hold the braked sheet on the plate after the suction braking force is removed.

15. A sheet feeding apparatus comprising means for conveying a plurality of sheets along a first path, sensing means responsive to a flaw in one of the sheets for directing said one sheet along a second path whereby a gap is formed between the sheets being fed along said iirst path, signal means associated with said first path to sense an excessive gap between the sheets being fed along said first path, suction means operated in response to said signal means for stopping and holding the sheet preceding the gap, said signal means being responsive to the sheet following the gap to render said suction means inoperable whereby said held sheet is released thereby to overlap the sheet preceding the gap with the following sheet.

16. A sheet feeding apparatus comprising means for conveying a plurality of sheets along a rst path, said first path including a plate onto which the advancing sheets are fed, said plate having an aperture therein, sensing means responsive to a flaw in one of the sheets for directing said one sheet along a second path whereby a gap is formed between the sheets being fed along said first path, signal means including a photoelectric device for sensing an excessive gap between the sheets being fed along said first path, suction means including a solenoid valve energizable in response to said signal means for introducing suction in the aperture in said plate to thereby stop and hold the sheet preceding the gap, said signal means being responsive to the sheet following the gap t0 de-energize said valve whereby the suction in said aperture is terminated and the held sheet is released thereby to overlap the sheet preceding the gap with the following sheet.

17. In sheet feeding apparatus including means for feeding a plurality of sheets along a predetermined path, means for deiiecting sheets out of said path, means fixed in position for selectively retarding and displacing the trailing edge of a sheet next preceding a deflected sheet as it passes a predetermined location in the sheet feeding path, said means including means for applying a suction force to the trailing edge of the sheet.

18. In sheet feeding apparatus, means for feeding web material, means for cutting said web material into a plurality of sheets, means for feeding said plurality of sheets along a predetermined path, means for selectively retarding and displacing the trailing edge of a sheet as it passes a predetermined location in the sheet feeding path, said means comprising a plate onto which each sheet is fed, said plate having an aperture therein to which suction is applied and means synchronized with the means for cutting the web material into sheets for applying the suction to the sheet through the aperture.

19. The apparatus as set forth in claim 18, wherein the means synchronized with the web cutting means comprises a rotatable drum having an aperture therein alignable with the plate aperture, and drive means for the drum synchronized with the web cutting means.

(References on following page) References Cited by the Examiner UNITED STATES PATENTS Evers 83-100 Barber 83-100 Broadmeyer 271-46 Belluche 271-46 Chamberlin et al. 83-88 X Belluche 271-68 Brintnall 271-68 Little 271-64 Braun 271-64 Moore 83--79 Snyder 198-35 10 Rapley 198-35 Beauliew 271-76 Kaddeland 271-74 X Coakley 198--35 Worwick 271--64 Claybourn 271-68 Schneider 271-68 X FOREIGN PATENTS 8/ 1934 Germany.

WILLIAM W. DYER, IR., Primary Examiner.

ANDREW R. JUHASZ, Examiner. 

5. A SHEET HANDLING AND STACKING APPARATUS COMPRISING MEANS TO CUT A WEB INTO A PLURALITY OF SHEETS, MEANS TO CONVEY SAID SHEETS ALONG A PATH AWAY FROM SAID CUTTING MEANS THEREBY DEVELOPING A NORMAL GAP BETWEEN SAID SHEETS, SUCTION MEANS FIXED IN POSITION AND ASSOCIATED WITH SAID CONVEYING MEANS TO RETARD AND DISPLACE EACH SHEET SO THAT THE LEADING EDGE OF A FOLLOWING SHEET OVERLAPS THE TRAILING EDGE OF EACH RETARDED SHEET, A STACKING DEVICE AND A MEANS TO CONVEY THE OVERLAP SHEETS TO SAID STACKING DEVICE. 